Material for and method of covering objects



July 14, 1936. H. vow FORSTER 2,647,655

MATERIAL FOR AND METHOD OF COVERING OBJECTS Filed Dec. 12, l934 2Sheets-Sheet 1 i 5 4 INVENTOR. HERMAN/Y VONFORSTER ATTORNEY.

Y uxgxm- July 14, 1936. H. VON FORSTER 2,047,655

MATERIAL FOR AND METHOD OF COVERING OBJECTS Filed Dec. 12, 1934 2Sheets-Sheet 2 INVENTOR. f/ERM/ /VN vo/v FORS TE R,

QQAIM ATTORNEY.

Patented July 14, 1936 MATERIAL FOR AND METHOD OF COVERING OBJECTSHermann von Forster, Niedcrursel, near Frankfort-on-the-Maln, Germany,minor to Vereinigte Deutsche Metallwerke Aktiengesellschaft,Frankfort-on-the-Main, corporation of Germany Germany, :1.

Application December 12, 1934, Serial No. 757,126 In Germany September5, 1930 4 Claims. (01. 108-6) The present invention relates to amaterial and method for covering roofs, walls and the like by means offoil-like, flexible, long and non-corrosive metal sheets and, moreparticularly, to a material and method for installing rooflngs of thedescribed type which are permanently attached to the base by means of apermanently plastic cementing mass intermediate to the metal sheet andthe base.

Heretofore, the installation of roofing materials has been effected insuch manner that first the base of wood-work or concrete or the like hasbeen covered by a thin layer of the hot plastic cementing mass andthereafter the metal sheets supplied in rolls similar to rolls of wallpaper have been spread out on the plastic mass and cemented thereto. Thelongitudinal edges of the adjoining sheets have been joined to eachother by means of folding. The operation of folding was rathertroublesome because the edges of the adjoining sheets had to be bent upand, consequently, a longitudinal margin had to be left uncoated by thecementing mass. Furthermore,

the cementing mass when spread all over the base in a thin layer usuallynot exceeding a few millimeters in thickness cooled all rather quicklydue especially to the good heat conductivity of the metal sheet. In viewof the quick cooling, the adhesion of the mass to the bright metallicsurface was considerably diminished. A further disadvantage was thatthere was danger that in time some moisture might enter the structurethrough the capillaries of the folds or through the holes of theretaining strips generally nailed to the base, even though the metalsheets were perfectly impermeable. Although attempts have been made toremedy the aforesaid disadvantages, no proposal, as far as I am aware,has been wholly practical, successful and satisfactory.

I discovered that the foregoing disadvantages can be eliminated in aremarkably simple way by providing the edges of the metal sheets with abend of appropriate form and by arranging the retaining strips withinthe folds itself and filling out the intervals in the fold with the sameplastic mass which is used for cementing the metal sheets to the base. Ihave also found that the adhesion of the metal sheets to the base isimproved if the cementing mass is not spread out in a thin layer on thebase before putting on the sheets, but a substantial amount or 'mound ofthe hot cementing mass is poured out directly in front of the roll ofsheet metal and then pushing the roll into the mound and causing the hotplastic mass to spread out ahead of the roll.

It is an object of the present invention to facilitate the installationof roofings of the type herein described.

It is another object of the present invention to provide an improvedfoil-like flexible metallic 5 roofing material in rolls similar to rollsof wall paper which can be easily installed and joined to other sheetsof the same type by means of folding.

It is a further object of the invention to provide a method of joiningadjacent sheets of the material and fastening same to the base in asimple and eflicient manner.

The invention also contemplates a method of putting on the plasticcementing mass between the metal sheet and the base.

Other objects and advantages of the invention will become apparent fromthe following description and the accompanying drawings in which:-

Fig. 1 is a perspective view, somewhat fragmentary, of a roofingmaterial embodying the principles of the invention;

Fig. 2 is a similar view of a sheet of roofing material and of aretaining strip for fastening same to the base;

Fig. 3 depicts perspectively two adjacent sheets of the roofing materialwhich are joined to each other by means of folding and are attached tothe base by means of a retaining strip and a thin layer of an adhesiveplastic mass;

Fig. 4 is a cross section of a roofing similar to the one shown in Fig.3 and made in the.plane of that drawing; and

Fig. 5 illustrates the manner in which the plastic cementing mass isintroduced between the metal sheet and the base.

Fig. 6 shows the roofing illustrated in Fig. 4 after the edge of theadjoining sheets are folded together to make a joint.

Referring now more particularly to Fig. 1, a wooden base is designatedby the reference character B which is to be covered by the metal sheets.Upon base B is a thin layer I of an adhesive permanently plastic masswhich bonds a metal sheet S thereto. An edge 3 of the metal sheets isbent back upwards before installing the sheet. I prefer to pre-bend thelongitudinal edges of the metal sheets at the plant where the sheets aremanufactured and before they are rolled upon or formed into rolls ordrums. I found that no flaws are formed when putting the pre-bent sheetson drums and the like provided the proportion of the thickness of thesheet to the diameter of the drum is selected properly even though thesheet near its edges will be of double thickness. For

1 by means of the plastic mass l.

example, copper sheets of 0.1 or 0.2 millimeter in thickness can bewound up and off drums of 400 millimeters in diameter without producingflaws, wrinkles or other deformations on the bent over edges of thesheets. thickness of the sheets used may vary between 0.5 and 0.1millimeter or less and, of course, the diameter of the drum ispreferably adapted to the sheet thickness.

The advantages of my invention can easily be appreciated when it isconsidered that with metal sheets of such type when applying thecementing mass it is not necessary to leave out a strip on the base. asstrip 2 in Fig. 1 but the complete surface may be covered with theplastic cementing mass and the sheet of metal is applied as shown in thedrawings. The adjoining sheet is applied in aisimilar manner so that itsbent edge comes close to that of the first sheet. After the sheets areapplied, the bent back edges of both sheets are bent upwards verticallyand are joined to each other by means of folding.

The adhesion provided by the permanently plastic cementing mass issufllcient to secure the metal sheet to the base. In somecases,'however, I prefer to provide additional protection of the sheetby arranging a retaining strip to the base by means of nails,pins or thelike. The arrangement of the retaining strip can be seen from Figs. 2and 3, showing the retaining strip and the two adjoining sheets inprogressive phases of the assembly. In Fig. 2, one of the sheets S hasits edges 3 bent back and is secured to the base B Hereafter retainingstrip 4 is laid flat on top of the edge of sheet S and fastened to thebase B, for example. by means of nails N as indicated in the drawings.After this, the sheet S is laid with its edge cover- .ing the retainingstrip in its full width and cemented to the base as indicated in Fig. 3.I found that if edges 3 and I of the sheets S and S and the free edge ofthe retaining strip 4 are folded together, in time some moisture mightenter the capillaries of the fold and under certain conditions mighteven reach the base. To eliminate this possibility of leakage, I preferto bend the edges 3 and I and the free edge of the retaining strip 4vertically upwards as shown in Fig. 4, fill out the intervals with theplastic cementing mass, and then firmly unite them by means of folding.The advantages of this procedure are obvious. The retaining strip isplaced inside of the fold and the holes in the same are not exposed tothe influence of rain or water. At the same time the fold itself iscompletely covered and coated with the plastic mass. In this manner,even the slight chance of some moisture entering the capillaries of thefold is completely eliminated and a perfectly impermeable roofing isprovided.

I have also found that it is of paramount importance that the cementingplastic mass should be hot and easily pliable at the moment the metalsheet is attached thereto. Previous to my invention this could not beaccomplished because the plastic mass has been first spread out on thebase in a thin layer of only 2 or 3 millimeters in thickness and thenthe sheets have been put on the base thus prepared. This prior procedurehad the disadvantage that the plastic cementing mass due to its thinnessand large surface cooled very rapidly, especially due to the great heatconductivity of the metal sheets employed, so that the sheets did notadhere well to the plastic cementing mass. According to the principlesof my inven- Generally speaking the tion, this difficulty is easilyovercome in a surprisingly simple way. As may be seen from Fig. 5, Ipour out a substantial amount of the hot cementing mass next to roll I lof the metal sheet 8 instead of spreading out the cementing mass on thesurface or base to be covered, so that due to its great consistency itwill form an accumulation or mound l0 which presses against the fullwidth of the roll of the metal sheet. The roll of metal sheet is thenrolled into this hot, plastic mound whereby the individual parts orparticles of the cementing mass will be rolled along and will be rubbedagainst the surface of the metal and by the pressure of the roll andwill be securely cemented thereto. Of course, the cementing mass adheresvery well to the non-metallic base and when due to the progress of theroll these adhering parts or particles are pushed ahead, theaccumulation of the hot, cementing mass before the roll will bemaintained. It is this constant accumulation of the cementing mass infront of the roll that has the greatest importance for the presentinvention. The uppermost parts or particles of the cementing mass adhereto the metallic surface and these adhering parts or particles take upsome more of the mass when the metal sheet is wound off from the roll.In this manner, the bright surface of the *metal will be uniformly andcompletely covered by the cementing mass. periment that when the hotcementing mass is simply spread out in a thin and uniform layer as thishas been in general practice heretofore and the metal sheet is thenapplied thereto, only 30 to 60% of the metallic surface is actuallycemented to the base, whereas according to the principles of the presentinvention a perfect, substantially 100% union of the metal with the baseis obtained. I also found that it is preferable to use a plasticcementing layer of approximately 1% to 2 millimeters in thiclmess.

I In addition, my invention provides other important advantages. It iseasily understood that a substantial accumulation or mound of the hotplastic mass will keep its high temperature much longer than a thinlayer of the same mass. Due to its great heat capacity, the cementingmass will heat up the metal sheet quite considerably during thecementing process. The metal sheet will expand and after cooling off andcontracting, it will lay smooth and under some tension due to the factthat the adhesion of a well cemented sheet to the base is veryconsiderable. Seasonal and daily changes in temperature cannot causedeformations of the metal sheet, because a renewed expansion of thesheet due to an increase in temperature will merely reduce the innertensions within the sheet.

The process of the present invention is of especial advantage ifvery-thin sheets of metal approximately 0.1 to 0.2 millimeter (0.004 to0.008 inches) in thickness are'preferredfor covering or insulatingstructural surfaces, although thicknesses up to about 0.5 mm. or evensomewhat greater (0.6'mm.) may be used. In general thicknesses greaterthan the 0.0005 .inch and less than 0.010 inch may be used. The amountof heat stored in the accumulation or mound of the cementing mass iscapable of increasing the temperature of such thin sheets veryconsiderably.

The invention provides a method of covering an object with acorrosion-proof, flexible and foldable metal in the form of a sheet offoil thickness and of sufficient mechanical strength to be handledwithout asupporting backing and.

I found by exslightly inclined surfaces.

to withstand the mechanical stresses to which it is subjected innormaluse but of less thickness and mechanical strength than is requiredof sheet metal roofing applied without adhesive attachment to theunderstructure and of securing the sheet directly to said surface bymeans of a hot mound of adhesive material. In carrying this inventioninto practice, it is contemplated to use a metal having such inherentflexibility and an adhesive having such inherent plasticity as to becapable of relative movement under differential thermal expansion andcontraction without separation from the surface or from the metalcovering.

Perfectly smooth covering surfaces of metal can thus be obtained also onirregular bases having cracks, bumps or holes. The principle of theinvention can be applied with success also to greatly inclined or evenperpendicular surfaces. In such cases, I prefer to start from the lowestpart of the surface and to move the roll of metal sheet upwards into thesubstantial accumulation or mound of the cementing mass poured outbefore the roll, whereby the same advantages are realized as in the caseof level or Of course the coverings made according to the principles ofthe invention may be also used as insulating layers insertedor embeddedin structures, for example tunnels and the like, to waterproof themagainst ground water or moisture. 1

In the present specification, I have described the preferred embodimentsof my invention but it is readily understood that many variations andmodifications are possible and will suggest themselves to those skilledin the art without departing from the spirit and scope of the inventionas defined in the appended claims.

I clai'm:--

1. The method of covering structural surfaces with sheets ofnon-corrosive metal of foil-like thickness and of accentuated lengthwhich coinprises positioning a roll ofmetal sheet on a base to becovered, pouring a hot cementing mass on said base immediately in frontof and next to said roll of metal sheet said mass having a verysubstantial volume and a relatively small cooling surface, rolling saidroll of metal sheet into said hot cementing mass at the same timeunwinding the sheet therefrom, pushing the portion of the cementingmassnot retained between the metal sheet and the base ahead of the roll in.the form of a substantial mound of considerable heat capacity adaptedto heat the unwinding sheet to preferred cementing temperatures, and

continuing said operation until the full length of the base is covered.

2. The method of covering structural surfaces with non-corrosive,foldable metal sheets of foillike thickness which comprises foldingbackwards the side edges of a-metal sheet of accentuated length to forma folded double marginal portion, rolling up said sheet to provide aroll having the said doubled marginal portion towards the inside,positioning said roll on a base to be covered, pouring a hot and plasticcementing mass on said base immediately in front of and next to saidroll of metal sheet said mass having a very substantial volume and arelatively small cooling hot cementing mass at the same time unwindingthe sheet therefrom, pushing the portion of the cementing mass notretained between the metal sheet and the base ahead of the roll in theform of a substantial mound of considerable heat capacity adapted toheat the unwinding metal sheet to preferred cementing temperatures, andcontinuing this operation until the full length of the sheet is firmlyand uniformly cemented to the base with the exception of the foldedmarginal portion which may be easily bent upwards for the purpose ofmaking a joint.

3.. The method of covering structural surfaces with non-corrosive metalsheets of foil-like thickness which comprises folding backwards the sideedges of a metal sheet of accentuated length to form a folded doublemarginal portion, rollingup said sheet to provide a roll having the saiddoubled marginal portion towards the inside, positioning said roll on abase to be covered, pouring a hot and plastic cementing mass on saidbase immediately in front of and next to said roll of metal sheet, saidmass having a very substantial .volume and a relatively small coolingsurface, rolling said roll of metal sheet into said hot cementing massat the same time unwinding the sheet therefrom, pushing the portion ofthe cementing mass not retained between the metal sheet and the baseahead of the roll in the form of a substantialmound of considerable heatcapacity adapted to heat the unwinding sheet to preferred cementingtemperatures, continuing this operation until the full length of thesheet is firmly and uniformly cemented to the base with the exception ofthe folded marginal portion, bending said uncemented, folded marginalportion of said sheet vertically upwards, and forming a joint with thecorresponding edge of another adjacent sheet prepared and laid on saidbase in similar manner.

4. The method of covering structural surfaces with non-corrosive metalsheets of foil-like thickness which comprises folding backwards the sideedges of a metal sheet of accentuated length to form a folded doublemarginal portion, rolling up said sheet to provide a roll, positioningsaid roll on a base to be covered, pouring a hot and plastic cementingmass on said base immediately in front of and next to said roll of metalsheet said mass having a very substantial volume and a relatively smallcooling surface, rolling said roll of metal sheet into said hotcementing mass at the same time unwinding the sheet therefrom,pushingthe portion of the cementing mass not retained between the metalsheet and the base ahead of the roll in the form of a substantial moundof considerable heat capacity adapted to heat the unwindingsheet topreferred cementing temperatures, continuing this operation until thefull length of the sheet is firmly and uniformly cemented to the base,preparing and laying another sheet adjacent to the first sheet in thesame manner, bending up the uncemented, folded marginal portion of saidsheets, placing a retaining strip between said sheets one edge of saidretaining strip being rigidly fastened to the base the other edge ofsaid retaining strip being bent upwards and arranged between the bent upedges of the covering sheets, filling the gaps between all three sideedges with a permanently plastic cementing mass and joining said edgestogether by means of folding.

HERMANN von FORSTER.

